Mast Cell Tumours in Dogs: Can PEA Help?

If your dog has been diagnosed with a mast cell tumour, you’re probably looking for anything that might help. Surgery and medication are the standard treatments, but there’s growing research on a natural compound called PEA (palmitoylethanolamide) that may provide additional support. This article explains what mast cell tumours are, what the research says about PEA, and how it might help your dog.

What Is a Mast Cell Tumour?

Mast cell tumours appear as raised lumps on or just under a dog’s skin. They can look red, swollen, or ulcerated. Some grow slowly over months while others seem to change size overnight. These tumours can also appear in the spleen, intestines, or bones, but skin tumours are most common. Mast cell tumours are actually the most common tumour type in dogs, and most dogs have only one. Any breed can develop them, but boxers, terriers, and labrador retrievers are more prone.

What Causes Mast Cell Tumours?

The short answer: nobody knows for certain. Veterinary medicine points to genetic mutations and environmental factors, but there’s no single identified cause. What we do know is what happens inside the tumour. Mast cells release granules packed with inflammatory chemicals when triggered. You’ll recognise one of these chemicals: histamine, the same thing that causes hay fever symptoms in humans. But mast cells also release leukotrienes, interleukins, and other inflammatory compounds. This is where PEA becomes relevant.

What the Research Says About PEA and Mast Cells

PEA (palmitoylethanolamide) is a fatty acid that dogs produce naturally. It plays a role in regulating inflammation and pain. Research has found that PEA directly affects mast cell activity.

Study 1: PEA Inhibits Mast Cell Chemicals in Dogs

A 2010 study specifically tested PEA on canine skin mast cells. The researchers triggered the mast cells to release their inflammatory chemicals, then measured what happened when PEA was present. The results:

“Histamine, PGD(2) and TNFalpha release, immunologically induced by canine anti-IgE, were significantly inhibited in the presence of PEA.”

In plain English: PEA significantly reduced the release of histamine and other inflammatory chemicals from dog mast cells. The study concluded:

“The results obtained in the present study showed the ability of the aliamide PEA to down-modulate skin mast cell activation.”

Source: Effects of palmitoylethanolamide on immunologically induced histamine, PGD2 and TNFalpha release from canine skin mast cells

Study 2: PEA Reduces Mast Cell Numbers and Activation

A 2019 study confirmed these findings and added more detail. The researchers found that PEA both reduces the increase in mast cell numbers and reduces how much inflammatory chemicals those cells release. Source: Palmitoylethanolamide counteracts substance P-induced mast cell activation in vitro

What This Means for Your Dog

The research shows PEA can:

1. Reduce mast cell activation – Mast cells are less likely to release their inflammatory payload

2. Lower histamine release – Less of the chemical that causes swelling, redness, and itching

3. Reduce other inflammatory chemicals – Including TNF-alpha and prostaglandins This doesn’t mean PEA cures mast cell tumours. Surgery remains the primary treatment for most cases, and some dogs need chemotherapy as well. But PEA may help by:

• Reducing inflammation around the tumour
• Making your dog more comfortable
• Supporting the body’s natural anti-inflammatory processes
• Working alongside conventional treatments without interactions

How to Use PEA for Dogs with Mast Cell Tumours

PEA comes as a tasteless powder that you sprinkle on your dog’s food once or twice daily. It takes about 2 weeks of consistent use to build up in the body. The standard dose is 10-20mg per kilogram of body weight per day. For a 30kg dog, that’s 300-600mg daily. PEA has no known side effects and no documented drug interactions. It can be used alongside antihistamines, steroids, and other medications your vet has prescribed.

For complete dosing information, see our guide to PEA for dogs.

A Note on Underlying Causes

While conventional medicine focuses on treating the tumour itself, it’s worth considering what might be triggering mast cell activation in the first place. Research on mast cells shows they’re part of the immune response to parasites. Studies have found that infections with various protozoa (single-celled parasites) cause an increase in both mast cell numbers and degranulation.

One common protozoan, T. gondii (toxoplasma), is found in many dogs. While we can’t say this causes mast cell tumours, ensuring your dog is treated for all parasites is a reasonable precaution with no downside.

Summary

Mast cell tumours are common in dogs and conventional treatment typically involves surgery and sometimes chemotherapy. Research shows that PEA directly inhibits mast cell activation and reduces the release of histamine and other inflammatory chemicals.

PEA won’t replace veterinary treatment, but it may help reduce inflammation and discomfort. It’s safe for long-term use and can be given alongside other medications.

If your dog has mast cell tumours, discuss PEA with your vet as a potential complement to their treatment plan.

References

1. Cerrato S, et al. (2010). Effects of palmitoylethanolamide on immunologically induced histamine, PGD2 and TNFalpha release from canine skin mast cells. PubMed

2. Petrosino S, et al. (2019). Palmitoylethanolamide counteracts substance P-induced mast cell activation in vitro. PubMed

3. Huang B, et al. (2017). The Roles of Mast Cells in Parasitic Protozoan Infections. PMC